Implement full MVP: auth, HD wallet, Electrum client, deposits, bets, round/draw engine, payout, withdrawals, RBF, admin+audit

All 10 build-order stages complete and unit-tested (49 tests). Verified live on
mainnet: registration/address derivation, deposit crediting, a real 10 PLM bet
(broadcast + confirmed + change credited). A full round close->draw->payout
cycle was triggered live and was in progress at commit time. Withdrawal and RBF
bump are unit-tested but not yet exercised against a live broadcast. Known gaps
(scheduler doesn't resume mid-flight rounds after restart, payout has no retry,
no deployment setup, etc.) are documented in CLAUDE.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/unit/test_confirmation.py

@@ -0,0 +1,82 @@
+import pytest
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+
+import app.bets.confirmation  # noqa: F401  (registers the "bet" handler)
+import app.rounds.confirmation  # noqa: F401  (registers the "payout" handler)
+from app.db.base import Base
+from app.db.models import PendingTransaction, Round, RoundParticipant
+from app.tx.confirmation import poll_once
+
+
+class FakeClient:
+    def __init__(self, confirmations_by_txid: dict[str, int]):
+        self._confirmations = confirmations_by_txid
+
+    async def get_transaction(self, txid: str, verbose: bool = False) -> dict:
+        return {"confirmations": self._confirmations.get(txid, 0)}
+
+
+@pytest.fixture
+async def session_factory():
+    engine = create_async_engine("sqlite+aiosqlite:///:memory:")
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+    yield async_sessionmaker(engine, expire_on_commit=False)
+    await engine.dispose()
+
+
+async def test_bet_confirmation_marks_participant_confirmed(session_factory):
+    async with session_factory() as session:
+        session.add(Round(id=1, status="open"))
+        session.add(
+            RoundParticipant(
+                round_id=1, user_id=1, bet_amount_sats=1_000, bet_txid="tx1", status="broadcast"
+            )
+        )
+        session.add(
+            PendingTransaction(kind="bet", round_id=1, user_id=1, current_txid="tx1", fee_rate_sat_vb=1, raw_tx_hex="00", status="pending")
+        )
+        await session.commit()
+
+    client = FakeClient({"tx1": 1})
+    confirmed = await poll_once(session_factory, client)
+    assert confirmed == 1
+
+    async with session_factory() as session:
+        participant = (await session.scalars(select(RoundParticipant))).one()
+        assert participant.status == "confirmed"
+        assert participant.confirmed_at is not None
+        pending = (await session.scalars(select(PendingTransaction))).one()
+        assert pending.status == "confirmed"
+
+
+async def test_unconfirmed_tx_is_left_pending(session_factory):
+    async with session_factory() as session:
+        session.add(Round(id=2, status="open"))
+        session.add(RoundParticipant(round_id=2, user_id=1, bet_amount_sats=1_000, bet_txid="tx2", status="broadcast"))
+        session.add(PendingTransaction(kind="bet", round_id=2, user_id=1, current_txid="tx2", fee_rate_sat_vb=1, raw_tx_hex="00", status="pending"))
+        await session.commit()
+
+    client = FakeClient({"tx2": 0})
+    confirmed = await poll_once(session_factory, client)
+    assert confirmed == 0
+
+    async with session_factory() as session:
+        participant = (await session.scalars(select(RoundParticipant))).one()
+        assert participant.status == "broadcast"
+
+
+async def test_payout_confirmation_closes_round(session_factory):
+    async with session_factory() as session:
+        session.add(Round(id=3, status="paying_out", payout_txid="tx3"))
+        session.add(PendingTransaction(kind="payout", round_id=3, current_txid="tx3", fee_rate_sat_vb=1, raw_tx_hex="00", status="pending"))
+        await session.commit()
+
+    client = FakeClient({"tx3": 2})
+    confirmed = await poll_once(session_factory, client)
+    assert confirmed == 1
+
+    async with session_factory() as session:
+        round_ = await session.get(Round, 3)
+        assert round_.status == "closed"